The present invention relates generally to an encapsulated angle-measuring apparatus for the measurement of angles of rotation, and in particular to such an apparatus for use with rotary or swinging tables having a rotation or swinging range of less than 360.degree., in which a graduation formed on a scale is scanned by a scanning unit.
It is a known practice to measure the angular position of a rotary or swinging table by means of a commercially available, attachable rotation indicator connected to the table. One such commercially available rotation indicator is described, for example, in the publication Inkrementale Drehgeber ROD; Program 78/79; 66 d 5 8/78 1E; published by Dr. Johannes Heidenhain GmbH, Traunreut, West Germany.
Often, however, such a rotation indicator is not readily adaptable for installation on a rotary table because of the geometry of the table. For example, when a swinging or rotary table is rotatably mounted on a hollow shaft, it may be difficult to adapt the table for use with a conventional rotation indicator.